Question: Khan.scratchpad.disable(); To move up to the maestro level in her piano school, Tiffany needs to master at least $156$ songs. Tiffany has already mastered $27$ songs. If Tiffany can master $6$ songs per month, what is the minimum number of months it will take her to move to the maestro level?
Answer: To solve this, let's set up an expression to show how many songs Tiffany will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Tiffany Needs to have at least $156$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 156$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 156$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 6 + 27 \geq 156$ $ x \cdot 6 \geq 156 - 27 $ $ x \cdot 6 \geq 129 $ $x \geq \dfrac{129}{6} \approx 21.50$ Since we only care about whole months that Tiffany has spent working, we round $21.50$ up to $22$ Tiffany must work for at least 22 months.